Department of Applied Quantum Physics and Nuclear Engineering, Faculty of Engineering, Kyushu University, Higashi-ku, Fukuoka, Japan.
Lab Chip. 2011 Oct 21;11(20):3479-86. doi: 10.1039/c1lc20261h. Epub 2011 Aug 25.
This paper presents a remote and preparation-free method of temperature imaging of aqueous solutions in microchannels of microfluidic chips. The principle of this method is based on the temperature dependency of the near-infrared (NIR) absorption band (ν(2) + ν(3) band) of water. Temperature images were constructed from absorbances in a narrow wavelength range including 1908 nm, the most sensitive to temperature in the band, measured by using an NIR camera and an optical narrow-bandpass filter. Calculation and calibration results demonstrated a linear relationship between the absorption coefficient and temperature with a temperature coefficient of 1.5 × 10(-2) K(-1) mm(-1). Temperature images of 50 μm thick water in a Y-shaped PDMS microchannel locally heated by a neighboring hot wire were obtained, in which thermal diffusion processes in the microchip were visualized. Temperature resolution was estimated to be approximately 0.2 K according to the temperature coefficient and noise level.
本文提出了一种无需远程准备即可对微流控芯片微通道中水溶液进行温度成像的方法。该方法的原理基于水的近红外（NIR）吸收带（ν(2) + ν(3) 带）的温度依赖性。通过使用近红外相机和光学窄带通滤波器测量在包括 1908nm 在内的窄波长范围内的吸收度来构建温度图像，该波长对温度最敏感。计算和校准结果表明，吸收系数与温度之间存在线性关系，温度系数为 1.5×10(-2) K(-1) mm(-1)。通过邻近热线局部加热的 Y 型 PDMS 微通道中 50μm 厚水的温度图像，可视化了微芯片中的热扩散过程。根据温度系数和噪声水平，估计温度分辨率约为 0.2K。
